It is experimentally challenging to directly obtain structural information of the transition state (TS), the high-energy bottleneck en route from reactants to products, for solution-phase reactions. Here, we use single-molecule experiments as well as high-level quantum chemical calculations to probe the TS of disulfide bond reduction, a bimolecular… (More)
The literature on gas phase nucleophilic substitution reactions at aliphatic carbon has been reviewed. The emphasis has been on journal articles published in the period 1990–2001. The present review outlines our current understanding of concepts such as potential energy surfaces, structure–energy relationships, microsolvation, and dynamical and mechanistic… (More)
The potential energy surfaces for the reaction between H2O and the protonated alcohols MeOH2+, EtOH2+, PriOH2+, and Bu(t)OH2+ have been explored by means of high level ab initio theoretical methods. Both nucleophilic substitution (SN2) and elimination (E2) pathways have been investigated. Front side (SNF) and the familiar back side (SNB) Walden inversion… (More)
Abundance mass spectra, obtained upon carefully electrospraying solutions of tert-butanol (TB) in water into a mass spectrometer, display a systematic series of peaks due to mixed H(+)(TB)m(H2O)n clusters. Clusters with m + n = 21 have higher abundance (magic number peaks) than their neighbours when m ≤ 9, while for m > 9 they have lower abundance. This… (More)
Large-scale on-the-fly Born-Oppenheimer molecular dynamics simulations using recent advances in linear scaling electronic structure theory and trajectory integration techniques have been performed for protonated water clusters around the magic number (H(2)O)(n)H(+) , for n = 20 and 21. Besides demonstrating the feasibility and efficiency of the… (More)
In this lecture/paper we will discuss the somewhat complicated relationship between theory and experiment in molecular science in general and mass spectrometry in particular, illustrated by some recent literature examples.
The gas phase reactions between HF and the protonated alkyl fluorides MeFH+, EtFH+, Pr(i)FH+, and Bu(t)FH+ have been studied using ab initio methods. The potential energy profiles for both nucleophilic substitution (S(N)2) and elimination (E2) pathways have been investigated. Both backside Walden inversion and frontside nucleophilic substitution reaction… (More)